This is a Phase I/IIa, open-label, multi-center, dose-escalation, and expansion study to evaluate the safety, tolerability, PK and preliminary anti-tumor activity of ASN-3186 when given orally in subjects with advanced solid tumors

Key Inclusion Criteria:

1. Males or females aged ≥ 18 years at time of signing informed consent form (ICF). Signed ICF must be obtained before the performance of any protocol-specified procedures.
2. Life expectancy ≥12 weeks evaluated by investigator.
3. ECOG Performance Score 0 to 2.
4. Histologically or cytologically confirmed advanced solid tumors defined as unresectable locally advanced or metastatic and do not have standard treatment available, or have disease progression on/after standard treatment, or cannot tolerate standard treatment.
5. For Phase Ia subjects: Subjects who have confirmed deleterious or suspected deleterious germline or somatic BRCAm, or HRRm, or HRD positive or other alterations are preferred, but gene alteration state is not mandatory as an inclusion criterion and no need to wait for biomarker detection results before enrollment.
6. For Phase Ib subjects: Subjects must have confirmed deleterious or suspected deleterious germline or somatic BRCAm, or HRRm, or HRD positive or other alterations.
7. For Phase IIa subjects: Subjects must have confirmed deleterious or suspected deleterious germline or somatic BRCAm, or HRRm, or HRD positive or other alterations.

Key Exclusion Criteria:

1． Treatment with any of the following:

1. . Prior treatment with any USP1 inhibitors.
2. . Prior treatment with radiotherapy, chemotherapy, targeted therapy or endocrine therapy within 4 weeks prior to the first dose of ASN-3186.
3. . Participated and received investigational therapy or used an investigational device or participated in a study of an investigational agent and received study therapy or used an investigational device within 4 weeks or 5 × t1/2, whichever is longer, prior to the first dose of ASN-3186.

2．Subjects who expect to require any other form of anti-tumor therapy during the treatment period. 3． Subjects who have unresolved toxicity greater than common terminology CTCAE V5.0 Grade 1 from prior anti-tumor therapy prior to the first dose of ASN-3186, except for alopecia and chemotherapy-induced peripheral neurotoxicity ≤ CTCAE V5.0 Grade 2. 4． Subjects who have undergone surgery on vital organs (other than aspiration biopsy) or suffered major trauma within 4 weeks prior to the first dose, or subjects who have not recovered from any surgical effect at screening, or subjects who are scheduled for major surgery during the study period. 5． Subjects who have gastrointestinal disorders that will affect oral administration or affect the absorption of ASN-3186 as judged by the investigator. Or subjects who have severe or clinically significant gastrointestinal disease (e.g., refractory diarrhea, intractable vomiting, colitis, etc.) within 4 weeks prior to the first dose of ASN-3186 and did not recover to CTCAE V5.0 Grade 1.